Target designator

ABSTRACT

A target designator for a guided weapon is disclosed. The designator has a sight arranged to display, in operation, a reticule superimposed upon a field of view. The reticule is moveable within the field of view. The designator further comprises an eye tracker operable to track the gaze of the operator whilst the operator uses the sight. The eye tracker communicates with the sight such that the reticule moves so as to be aligned with the direction of the gaze of the operator.

FIELD OF THE INVENTION

This invention relates to a handheld target designator for a guidedweapon. More particularly, but not exclusively, the invention relates totarget designators in which eye-tracking is used to designate a targetto the guided weapon.

BACKGROUND

Guided weapons make use of sensors and guidance algorithms to guidethem, once launched, towards a designated target. Occasionally, it maybe possible for target designation to occur automatically (for example,the designation of an aircraft silhouetted against a clear sky), but inmany cases it will be necessary for an operator to designate the targetto the weapon. Currently this is done by means of a targeting reticule.In some cases the reticule may be fixed to the launcher, such that thecrosshairs are permanently fixed to the boresight of the weapon. Targetdesignation is then achieved by moving the launcher until the crosshairsare over the target. In other cases a moving reticule is provided, sothat the operator can move the reticule by means of a hand control, suchas a joystick, using the whole hand, or sticks or D-pads, for which onlythe operator's thumbs are required.

However, both fixed and moveable reticule systems suffer from problemsin target designation. In the case of handheld systems, using fixedreticules, particularly where the weapon and launch system is heavy,selection of a small target in a relatively large and cluttered field ofview can be difficult, because the whole system must be moved in orderto set the target. This makes fine movements, which may be difficultwhere the target is relatively small within the field of view,difficult. In contrast, the provision of a moving reticule can assist insuch fine movements. However, for the operator to perform fine controlmovements of the reticule using thumbs, whilst using both hands to holdand steady a guided weapon system (weighing potentially tens ofkilograms) can be difficult, and may be impossible where the operator ison a moving and unsteady platform. Similar problems exist for otherweapon systems used when the operator is required to hold otherequipment steady whilst designating a target; or where the operator ismoving across ground on foot whilst attempting to designate a target.

SUMMARY OF THE INVENTION

In accordance with a first aspect of the invention, there is provided atarget designator for a guided weapon, the designator having a sightarranged to display, in operation, a reticule superimposed upon a fieldof view, the reticule being moveable relative to the field of view; thedesignator further comprising an eye tracker operable to track the gazeof the operator whilst the operator uses the sight; and the eye trackerbeing in communication with the sight such that the reticule moves so asto be aligned with the direction of the gaze of the operator.

The provision of a reticule that can be moved by the operator simply bymoving direction of gaze enables the target designator to be operated ina number of scenarios where previously operation would not be possible.For example, the designator can be operated whilst the operator is on amoving or unsteady platform, and the operator is moreover able todesignate moving targets, since the operator's gaze will remain focussedon the desired target, whereas very delicate hand control (verydifficult when the operator is on a moving or unsteady platform,supporting the launcher, and impracticable in a combat situation) wouldbe required to designate a moving target for prior known systems. Evenon stable ground the operator's own small scale movements, resultingsimply from breathing, or hand tremble, may impose a significant erroron long range targeting, which would be obviated through the use of eyetracking for target designation. In addition, the target designator canbe used whilst the operator is running or walking across ground, whereagain fine hand control may not be possible. In such a situation it willbe appreciated that the designator may be remote from the weapon itself.Thus the target designator is operable against a greater number oftargets and provides the operator with a greater degree of flexibilityin combat situations.

The eye tracker may be a wearable device. Wearable eye trackers arecommercially available and thus have the advantage of simplicity. It isenvisaged that it may be preferable for the eye tracker to be integratedwith the sight so as to reduce the overall load that the operator isrequired to carry. Thus, for example, the eye tracker and sight may beintegrated into a helmet-mounted system, communicating with a remoteweapon system.

The eye tracker may be mounted on the sight. The sight may be atelescopic device through which the field of view is visible. Forexample, the target designator may be incorporated onto a handheldlauncher for a guided weapon, and the eye tracker retrofitted to anexisting sight. In such embodiments, the operator's field of view maydiffer from the view of the weapon's sensors, such that the weapon mayperform additional processing in order for the target on which theoperator's gaze is focussed to be designated as a target to the weapon.Such processing can be readily implemented in software, and as a resultsuch embodiments can be readily retrofitted as improvements to existingsystems.

The guided weapon may be provided with a camera, and the field of viewdisplayed by the sight may be provided by the camera. In suchembodiments, the operator's view is the same as that of the weapon, sothat the operator can designate a target directly to the weapon, usingthe same image source as the weapon's guidance algorithms.

The eye tracker may be associated with a processor configured torecognise one or more eye gestures, and to control the sight such thatthe field of view displayed by the sight is altered in response to theone or more eye gestures. The use of eye gestures to control the sightremoves the need for the use of certain other user interactionmechanisms for that purpose, enabling the field of view to be alteredwithout the use of hand control. As with targeting, use of hand controlmay be difficult in circumstances where the operator is stood on amoving or unsteady platform, or where the operator is otherwiseencumbered. For example, one of the one or more eye gestures may causethe sight to zoom in on a portion of the field of view. It will beappreciated that the mechanism by which the zoom is accomplished may beinternal to the sight (where the sight is a telescopic device) or may beachieved by a camera (where the sight provides a field of view from acamera which, for example, may be a part of a weapon sensor cluster).The ability to zoom in on a particular region of the field of view,without the need for operation of any controls by hand, has been foundto be particularly useful where targets that are relatively small withinthe field of view (having dimensions of, say, only a few pixels across)are to be designators. Zooming in enables more accurate designation ofsuch targets. One of the one or more eye gestures may cause the sight tomove the field of view. One of the one or more eye gestures may causethe sight to zoom out.

The display may be configured to zoom either in or out depending on theposition of the operator's gaze within the field of view. The displaymay have first and second regions, and the display may zoom in when theoperator's gaze lingers in a first region, and zoom out when theoperator's gaze lingers in a second region. The rate of zoom may bedependent on a distance between the operator's gaze and the boundarybetween the first and second regions.

The designator may further comprise a trigger device, and the designatormay be configured such that, upon a first operation on the triggerdevice, the weapon selects as a target an object on which the reticuleis centred.

The designator may be configured to detect when the operator's gazesettles on a particular object for longer than a predetermined period oftime, and to designate that object to the guided weapon as a target.

The designator may comprise communication means for communicating with aremote weapon such that a target can be designated to the remote weapon.Similar advantages to those described above are achieved for designationof targets to remote weapons, when designation is to be performed by anoperator either encumbered by other equipment or loads, or a movingoperator.

The target designator may be a handheld target designator

The invention extends to a handheld launcher for a guided weaponcomprising a designator as described above.

BRIEF DESCRIPTION OF THE DRAWINGS

There follows, by way of example only, a detailed description of aspecific embodiment of the invention with reference to the accompanyingdrawings in which:

FIG. 1 is a schematic illustration of a handheld launcher in accordancewith a first embodiment of an invention;

FIGS. 2A and 2B are schematic illustrations of an operator view througha sight associated with the handheld launcher illustrated in FIG. 1;

FIG. 3 is a schematic illustration of the handheld launcher of FIG. 1 inuse; and

FIG. 4 is a schematic illustration of an operator view through analternative sight for use with the handheld launcher illustrated in FIG.1.

Like reference numerals are used to designate like parts throughout theaccompanying drawings.

DETAILED DESCRIPTION

Target designators according to embodiments of the present invention areexpected to find application in a variety of situations where presentlyknown systems are either difficult or impracticable to operate. Oneexemplary embodiment of a target designator will now be described, inwhich the target designator is incorporated into a handheld launcher fora guided weapon.

Handheld launcher 100 is illustrated in FIG. 1, and comprises launchtube 110, sight 120, and trigger 130. The launcher 100 is shown withweapon 150 mounted in tube 110 ready for launch. Launch of the weapon150 is commenced on activation of the trigger 130 which, in the presentembodiment, is a two-pull trigger. Weapon 150 is a guided weapon, andcomprises a sensor cluster 160 mounted in the nose region of the weapon,as well as an on-board processor able to perform guidance algorithmssuch that on launch, the weapon is guided towards a target designated toit by an operator, such as target 230 (as shown in FIGS. 2A and 2B). Thesensor cluster 160 includes a camera which, when the weapon 150 ismounted in the launcher 100, feeds an image of the scene in the camerafield of view to the sight, so that the operator's view through thesight is that of the weapon's sensor cluster. As shown in FIG. 1, thesight 120 is mounted on the launch tube 110 and is positioned such thatthe operator can look into the sight whilst supporting the launcher andweapon on a shoulder and steadying it using hands.

Sight 120 in addition comprises an eye tracker 140 that is integratedinto the sight so as to be operable to track the movements of theoperator's gaze whilst the operator views the scene displayed by thesight. A schematic illustration of the operator's view through thesight, prior to the first pull of the trigger 130 is shown in FIG. 2A.The view includes the scene 210 as imaged by the weapons sensor cluster160.

The first pull of the trigger causes the sight to display a reticule 220superimposed over the scene 210, as is illustrated in FIG. 2B. Theposition of the reticule 220 is determined by the direction of theoperator's gaze, as measured by the eye-tracker 140. When the directionof the operator's gaze changes, the position of the reticule 220 in thesight changes so as to be centred on the point in the scene 210 on whichthe operator is focussing attention. Thus, by gazing at the target, theoperator is able to move the reticule 220 over the target. Once thecorrect target is centred in the reticule 220, the operator performs thesecond pull of the trigger in order to designate the target to theweapon, and launch the weapon.

In the present embodiment certain aspects of the sight can be controlledby eye gestures such that the operator can control the sight without theneed to use hands. The eye gestures are predefined in software andrecognised from the output of the eye tracker. Thus, when theeye-tracker records that the gaze of the operator is remaining near anedge of the scene displayed by the sight, the field of view displayed bythe sight can be panned in that direction. If the operator's gazeremains fixed on a certain point within the scene without a target beingdesignated by a second pull of the trigger, the sight can zoom (eitheroptically or, if the sensor cluster 160 is not able to optically zoom,digitally) in on that region in order to magnify it. Alternatively, ifthe operators gaze wanders around the periphery of the displayed scene,the sight will zoom out so as to display a wider field of view to theoperator.

FIG. 3 is a schematic illustration of how the above-described embodimentmay be used. An operator 300 holds launcher system 100 whilst standingin a moving vehicle 310. Target 230 is an enemy moving vehicle. Theoperator is able to designate the target by focussing his gaze on it,and then launch the weapon such that the weapon's guidance system guidesit towards the target. Designation of the moving target is only possiblebecause no hand control or thumb controls are required to designate thetarget: the fine movements required to designate the target to theweapon are very difficult when the operator is standing on anunpredictably moving platform, and impracticable in a combat situation.

FIG. 4 is a schematic illustration of an operator view through analternative sight that can be used with a handheld launcher as describedabove. Sight 400 is divided into regions 410 and 420, separated by aboundary indicated by dashed line 430. Region 410 is a circular regionaround the centre of the sight 400, whilst region 420 covers theperipheral regions of the sight.

A human operator of a handheld launcher or complex weapon, for examplelauncher 100 illustrated in FIG. 1, may be required to find and identifya target and cue the guidance strategy. The combination of target sizeand the sighting system field of view may conspire to make the targetappear small in the targeting frame. A small target at some distancefrom the weapon may only occupy a few pixels of the sighting system,which will not only make it hard to find in the frame but also oncefound the low resolution and small size will also make it hard toidentify. Furthermore, once found and identified it may be hard toaccurately place the targeting reticule upon a target that only occupiesa very small portion of the screen.

The portion of the screen that contains the target can be enlargedthrough either an optical zoom to increase the resolution of the targetor through a digital zoom to simply increase its apparent size in theframe without an associated increase in resolution. Both of thesemethods of zooming the display can be of great advantage to the operatorin the effort to identify the target and to cue the weapon. For example,an optical zoom will enable the operator to better resolve the targetand therefore improves the ability to identify it. For example, if adigital zoom is employed the intended target remains unresolved butconsumes a large portion of the targeting frame. In this case theability of the operator to place the targeting reticule on that targetis greatly improved.

In the present embodiment alternative eye gestures are used to provokethis display zooming behaviour. The basis of the present zoom control isthrough a measure of how long the operator's gaze, indicatedschematically at 440 in FIG. 4, lingers on a particular portion of thescreen. If the operator's gaze remains focussed upon the central region410 of the targeting frame, the weapon sights will zoom into that partof the display. If the operator's gaze is around the peripheral regionof the display 420, the weapon sight will zoom out.

When the operator's gaze is near to the centre of the targeting frame inregion 410, the display will zoom in at it maximum rate until it reachesa suitable maximum size. If the operator's gaze inhabits the extremeedge of the screen in region 420, or outside the screen, the displaywill zoom out at its maximum rate until the entire field of view isvisible. When the gaze lingers between these two limits the zoom rateand direction will be moderated depending upon whether the gaze inhabitsregion 410 or region 420.

The boundary 430 between regions 410 and 420 marks the transitionbetween zooming in and zooming out. The zoom rate at this boundary istherefore zero. The distance from boundary 430 and the centre of theinner region 410 will moderate how fast the display will zoom in. Nearthe boundary 410 the rate at which the display will zoom in will beminimal. As the eye moves further from the boundary 410, towards thecentre of the screen the zoom rate inwards will increase until a maximumzoom rate selected for the specific implementation is reached. Note thatthe enlargement of the display may have the effect of drawing the objectof interest to the centre of the screen, reinforcing the increase of thezoom rate towards the object of interest. The boundary 430 may bevisible or not visible to the operator. The boundary 430 can varydepending on whether the eye is moving from inner region 410 to outer420 or vice versa. There may in some further embodiments be a boundaryregion of defined thickeness, rather than a boundary line, exhibiting nozoom.

If the gaze lingers in region 420, near to the boundary 430, the displaywill zoom out slowly. As the gaze moves away from this boundary 430towards the edge of the screen the zoom rate will increase. At the edgeof the targeting frame, when the gaze is as far from boundary 430 aspossible, the display will zoom out at its maximum rate.

In a variation of this technique, the position of the inner region ismanaged depending upon where the operator gaze lingers. The inner region410 may slowly drift towards the gaze point, imposing an increasing zoomupon this focus.

In a further variation of this technique, the size, shape or zoom rateof the inner region 410 may be varied depending upon the gaze behaviour.For example, if the gaze focuses upon a feature on the display, theprocess above may provoke a zoom into this feature. However, as the gazelingers upon this feature the size of the inner region 410 may shrink,facilitating a rapid zoom out should the operators focus move elsewhere.

In further variations, the total amount of zoom, rather than the zoomrate, is managed by the gaze position in a similar manner.

Whilst a specific embodiment of the invention has been described in theabove, it is to be noted that variations and modifications to thatembodiment are possible without departing from the scope of the presentinvention, which is defined in the accompanying claims. For example,whilst it has been described in the above to integrate the eye trackerwith the sight on a handheld launcher, it will be appreciated that theeye tracker may instead be helmet mounted and separate from the launchersystem, communicating with the launcher system either via a wiredconnection or wirelessly. In such cases the sight may be provided by ahelmet mounted display, showing a moving reticule, or by a separatetelescopic device. Commercial-off-the-shelf eye tracking systems,available from suppliers such as Tobii® are of sufficient performance toenable eye tracking in such a manner.

Such helmet mounted systems may also be used to designate a target to aremote weapon. For example, an operator on the ground, wearing a helmetmounted eye tracker can gaze at a desired target and designate thattarget to the weapon either by a two pull, handheld trigger, similar tothat described in the above. Such target designators will besignificantly easier to use than hand controlled designation means,where fine control is needed to designate the correct target. The remoteweapon may be either launched from a remote battery, several kilometresaway from the operator, from an aircraft in the vicinity of theoperator, or from an alternative remote location. Such targetdesignators will be easier to use than existing systems, particularlywhere the operator is encumbered by other equipment, such as a riflepack, or by the need to carry other heavy loads, such as a stretcher ora wounded colleague.

Moreover, the skilled person will recognise that alternative targetdesignation mechanisms will be possible. For example, rather than use amanually operated trigger to designate the target, the target mayautomatically be designated when the operator's gaze stays fixed on aparticular object for longer than a certain period of time, if adefinite object can be recognised by image analysis algorithms, or whenthe operator performs an alternative predefined eye gesture, such as awink. The period of time may be configurable by the operator, but isanticipated to be more than one second. The reticule may be displayedpermanently in the sight, or when the sight detects that it is in use(for example through recognising that an operator is close by), ratherthan only when a trigger is pulled for a first time. Target designationcan then be confirmed by the action of the operator pulling the triggerto launch the weapon. In the event that an incorrect target isdesignated, a correction can be applied by recognising either that theoperator's gaze is no longer fixed on the same point, or the designationcan be cancelled if the weapon is not launched within a predeterminedtime period (for example, three seconds).

The invention claimed is:
 1. A target designator for a guided weapon,the designator comprising a sight arranged to display, in operation, areticule superimposed upon a field of view, the reticule being moveablerelative to the field of view; and an eye tracker operable to track thegaze of the operator whilst the operator uses the sight, the eye trackerbeing in communication with the sight such that the reticule moves so asto be aligned with the direction of the gaze of the operator, whereinthe eye tracker is associated with a processor configured to recogniseone or more eye gestures, and to control the sight such that the fieldof view displayed by the sight is altered in response to the one or moreeye gestures, and wherein one of the one or more eye gestures causes thesight to zoom in on a portion of the field of view.
 2. A designator asclaimed in claim 1, wherein the eye tracker is mounted on the sight. 3.A designator as claimed in claim 1, wherein the eye tracker is awearable device.
 4. A designator as claimed in claim 1, wherein thesight is a telescopic device through which the field of view is visible.5. A designator as claimed in claim 1, wherein the guided weapon isprovided with a camera, and wherein the field of view displayed by thesight is provided by the camera.
 6. A designator as claimed in claim 1,wherein one of the one or more eye gestures causes the sight to move thefield of view.
 7. A designator as claimed in claim 1, wherein one of theone or more eye gestures causes the sight to zoom out.
 8. A designatoras claimed in claim 1, wherein the designator is configured to detectwhen the operator's gaze settles on a particular object for longer thana predetermined period of time, and to designate that object to theguided weapon as a target.
 9. A designator as claimed in claim 1,wherein the designator comprises communication means for communicatingwith a remote weapon such that a target can be designated to the remoteweapon.
 10. A target designator as claimed in claim 1, wherein thedesignator is a handheld target designator.
 11. A handheld launcher fora guided weapon comprising a designator as claimed in claim
 1. 12. Atarget designator for a guided weapon, the designator comprising a sightarranged to display, in operation, a reticule superimposed upon a fieldof view, the reticule being moveable relative to the field of view; andan eye tracker operable to track the gaze of the operator whilst theoperator uses the sight, the eye tracker being in communication with thesight such that the reticule moves so as to be aligned with thedirection of the gaze of the operator, wherein the display is configuredto zoom either in or out depending on the position of the operator'sgaze within the field of view.
 13. A designator as claimed in claim 12wherein the display has first and second regions, and wherein thedisplay will zoom in when the operator's gaze lingers in a first region,and zooms out when the operator's gaze lingers in a second region.
 14. Adesignator as claimed in claim 13 wherein the rate of zoom is dependenton a distance between the operator's gaze and the boundary between thefirst and second regions.
 15. A target designator for a guided weapon,the designator comprising a sight arranged to display, in operation, areticule superimposed upon a field of view, the reticule being moveablerelative to the field of view; an eye tracker operable to track the gazeof the operator whilst the operator uses the sight, the eye trackerbeing in communication with the sight such that the reticule moves so asto be aligned with the direction of the gaze of the operator; and atrigger device, wherein the designator is configured such that, upon afirst operation on the trigger device, the weapon selects as a target anobject on which the reticule is centred.